INS and obesity due to melanocortin 4 receptor deficiency: As a risk factor for insufficient sensitivity to insulin, the importance of obesity has been established.2 Obesity is also reported to be associated with health problems such as cancer and cardiovascular disease.3 The body mass index (BMI), waist circumference (WC), and WC/Height (Ht) ratio have been used as indices of obesity for a long time.4,5 However, these traditional anthropometric indices cannot distinguish between mass containing fat (fat mass) and fat-free mass, making accurate classification of risk for obesity-related complications difficult.6,7